Color blindness is a sex-linked trait. As such, if a child is color blind, we can be assured that the child's genotype includes:
A) a recessive gene on the X chromosome inherited from his mother
B) a dominant gene on the X chromosome inherited from his mother
C) a recessive gene on the Y chromosome inherited from his father
D) a dominant gene on the X chromosome inherited from his father

Question

Quizplus · Accepted Answer

Color blindness is caused by a recessive X-linked gene, meaning that it is carried on the X chromosome. Since males have only one X chromosome, if they inherit the recessive gene from their mother, they will be color blind. Females, on the other hand, would need to inherit two copies of the recessive gene (one from each parent) to be color blind.

Color Blindness Is a Sex-Linked Trait